i've played with peltiers to chill the water but they are VERY inefficient and can lead to a lot more problems than they are worth, also with a chiller setup you will need two cooling loops. one to cool the peltier and the other to deliver cold water to whatever you are cooling, this setup also requires 3 heat exchangers before you even get to whatever you are cooling.
while still on the subject of watercooling i should mention that you should only use distilled or demineralised water to fill or top up the loop. any additives are only to stop nasties from growing weather it be a cap full of metho or ordinary car coolant (use car coolant if there are dissimilar metals in the cooling loop to stop corrosion.)
i hope all this "do this, dont do that" hasn't put you off lol
anyway i must fetch my pc a glass of water.